97 SE With Error Code 42 (P1388 or P1389)

[SSTJ]

My FSM doesn't provide a P_ _ _ _ alternative for this code. For code 42, it just says "Auto Shutdown Relay Control Circuit", and "An open or shorted condition detected in the auto shutdown relay circuit."

Don't know what to do about this. Any advice?

Edit: I actually see four different entries for #42 in the table on 25–3 of my 97 FSM. Shown below.

Edit: Over here, it looks like the matching P-codes are P1388 or P1389. Anyone ever worked on those?

 

[Steel City 06]

Swap the fuel pump and ASD relays with other random relays in the PDC and see if the issue persists. The relays are all identical, so one that operates your fog lights for example should also work for the ASD.

 

[SSTJ]

Swap the fuel pump and ASD relays with other random relays in the PDC and see if the issue persists. The relays are all identical, so one that operates your fog lights for example should also work for the ASD.

Interesting, thanks! Will do.

 

[SSTJ]

Swap the fuel pump and ASD relays with other random relays in the PDC and see if the issue persists. The relays are all identical, so one that operates your fog lights for example should also work for the ASD.

Thanks again.

I swapped the ASD relay with the Horn relay, and I can still honk. So I guess that the relay is fine. Or, let me know if I'm misunderstanding anything.

 

[Jerry Bransford]

After what all you've done I wonder if your PCM might be the root cause of that problem. I'd give @Mark cantrell at www.wranglerfix.com a call to chat with him about it. The PCM is what controls the ASD relay.

 

[SSTJ]

After what all you've done I wonder if your PCM might be the root cause of that problem. I'd give @Mark cantrell at www.wranglerfix.com a call to chat with him about it. The PCM is what controls the ASD relay.

Thanks Jerry. I may do that.

But first, since I see that this code (42) can mean a few different things, I'm going to get a scan tool and see what more information I can get. Looking at the screenshots I posted in my first post, I see that the "scan tool display" column is different for a few of these, so maybe I'll be able to find out that way.

 

[Jerry Bransford]

An external code reader is unlikely to give any more useful advice than the 42 code did. Early TJs only provided two digit DTCs (diagnostic trouble codes) so there weren't as many of them as are there P0000 codes for 2000 and newer TJs but that 42 is as descriptive as any of the four digit codes would be for that problem.

 

[SSTJ]

An external code reader is unlikely to give any more useful advice than the 42 code did. Early TJs only provided two digit DTCs (diagnostic trouble codes) so there weren't as many of them as are there P0000 codes for 2000 and newer TJs but that 42 is as descriptive as any of the four digit codes would be for that problem.

Thanks Jerry.

So, in my original screenshots, the third column is called something like “scan tool display”. That column is different for some of the 42s.

So I was hoping that means scan tools provide something more than just the code itself. Not true?

 

[TJ Jim]

You didn’t state whether the Jeep runs? If it runs that might tell it’s not fuel pump related.

 

[SSTJ]

You didn’t state whether the Jeep runs? If it runs that might tell it’s not fuel pump related.

Thanks. Yep, running fine.

 

[SSTJ]

Bump. Anyone ever done any troubleshooting on this? Found the matching P-codes and updated the original post.

 

[SSTJ]

An external code reader is unlikely to give any more useful advice than the 42 code did. Early TJs only provided two digit DTCs (diagnostic trouble codes) so there weren't as many of them as are there P0000 codes for 2000 and newer TJs but that 42 is as descriptive as any of the four digit codes would be for that problem.

Thanks Jerry.

So, in my original screenshots, the third column is called something like “scan tool display”. That column is different for some of the 42s.

So I was hoping that means scan tools provide something more than just the code itself. Not true?

Hi Jerry. So, over in our other thread, you'll remember that my scan tool isn't showing all of the same codes as my MIL on the dash. But at least I did learn that the scan tool provides more information than just a number. It provided a text-based description of the problem, like in the final columns of my screenshots above.

So if I can just find a scanner that actually gives me this DTC (42), I'm hoping it'll have some more info soon.

 

[Jerry Bransford]

I don't know If you already found the definition of the 42 code but this guide gives it and all the other early DTC code definitions. https://www.offroaders.com/tech/jeep/TJ_diagnostic_codes.htm

 

[SSTJ]

I don't know If you already found the definition of the 42 code but this guide gives it and all the other early DTC code definitions. https://www.offroaders.com/tech/jeep/TJ_diagnostic_codes.htm

Thanks. Looks pretty consistent with the screenshots of my FSM in the original post, right?

 

[Jerry Bransford]

Thanks. Looks pretty consistent with the screenshots of my FSM in the original post, right?

Oh crap that's what I get when responding from my cellphone.

 

[RMETeeJay]

If the code comes back after a reset, then test all of the components described in your first post to determine the cause.

 

[SSTJ]

This code went away shortly after I swapped my horn relay and ASD relay. Will return to this thread if it ever comes back.

 

[DaYooperTransplant]

This code went away shortly after I swapped my horn relay and ASD relay. Will return to this thread if it ever comes back.

SSTJ, I got the P1389 Tuesday evening and I'm wondering if you had anymore issues with yours?

In my case, I had installed a toggle switch on the wire between the PCM and ASD relay several years ago, so that's where I started with troubleshooting. It seems like my cheap toggle may have wore out and was causing it to flicker between open/closed. I also removed and cleaned up the Distributor Pickup, checked the plugs and wires and also inspected any visible wiring in the harness. It started back up and I drove around the neighborhood. Didn't want to get too far as I had no one to tow me back. Seemed to run fine though.

Just wanted to see if there were other things you came across that I should also look into.

Thanks.

 

[SSTJ]

Hi @DaYooperTransplant

I actually haven't thought about this since I wrote that post last year. So, nothing more to share from my experience.